I know this topic has been beat to death but what do I need to get my speedometer reading accurately? Do I have to get numbers off the housing where the cable threads into the trany? What info do I need to provide the supplier? Where's the best place to purchase the gears?

 

Two ways I know of to do it. One is to start with your gear pair. Figure out what the tooth count is on your current gear set. Determine how much you want to change, up or down. There are several on line resources that sell gears that have a calculator function that will tell you what gears to buy based on the information you supply.

The other way is to do measure your tire diameter, determine your axle ratio, final drive ratio of the trans and look through those same websites and tables to find a gear set. I just bought a bunch of stuff from Kerry at www.laspeedometergear.com Best price and quick service. I'm sure if all else fails, a phone call to him will sort you out.

Tim

 

Tci has a gear calculator.
http://www.tciauto.com/tc/speedometer-gear-calculator/
You need to know rear tire diameter and read gear ratio and number of teeth on the drive gear.
I had to change both gears which means dropping the driveline and removing the tail of the tranny. If not off by much you might get away with just changing the one at the end of the speedo.

 

you can install a gear ratio adapter to the outside of the case withoutever opening up the tail. All you need to know is the percentage it's off. I'm going this route pretty soon myself. I'll let you know unless you beat me to it. I've heard people have a problem with them leaking a little bit. You can find them here about halfway down the page http://www.transmissioncenter.net/sp...____va.htm#400 part# #54RA, Ratio Adapter